Dictionary of Agricultural Microbiology and Virology. Thematic plan of discipline
- The subject of microbiology and its importance for agricultural production
Microbiology (from micro... and biology ), the science that studies microorganisms bacteria, mycoplasmas, actinomycetes, yeast , microscopic mushrooms and algae - their systematics, morphology, physiology, biochemistry, heredity and variability, distribution and role in the circulation of substances in nature, practical significance.
The development of microbiology and the needs of practice led to the separation of a number of sections of microbiology into independent scientific disciplines. General microbiologist AI studies the fundamental regularities of the biology of microorganisms. Knowledge of the basics of general microbiology is necessary when working in any of the special sections of microbiology.
Agricultural microbiology finds out the composition of soil microflora, its role in the circulation of substances in the soil, as well as its significance for the structure and fertility of the soil, the effect of processing on microbiological processes in it, the effect of bacterial preparations on plant productivity. In the task of s.-x. microbiology includes the study of microorganisms that cause plant diseases, and the fight against them, the development of microbiological methods of controlling insect pests of agricultural crops. plants and forest species, as well as methods of fodder conservation, flax lobe, crop protection from spoilage caused by microorganisms.
To the task technical or industrial microbiology includes the study and implementation of microbiological processes used to obtain yeast, feed protein, lipids, bacterial fertilizers, as well as the production of antibiotics, vitamins, enzymes, amino acids, nucleotides, organic acids, etc. by microbiological synthesis. Geological microbiology studies the role of microorganisms in the circulation of substances in nature, in the formation and destruction of mineral deposits, and proposes methods for obtaining (leaching) metals (copper, germanium, uranium, tin) and other minerals from ores with the help of bacteria. Aquatic microbiology studies the quantitative and qualitative composition of the microflora of salt and fresh waters and its role in the biochemical processes occurring in reservoirs, monitors the quality of drinking water, improves microbiological methods of wastewater treatment. To the task medical microbiology includes the study of microorganisms that cause human diseases and the development of effective methods to combat them. The same questions regarding agricultural and other animals are solved veterinary microbiology.
The practical importance of microbiology. Actively participating in the circulation of substances in nature, microorganisms play an important role in soil fertility, in the productivity of water bodies, in the formation and destruction of mineral deposits. The ability of microorganisms to mineralize the organic remains of animals and plants is especially important. The ever-increasing use of microorganisms in practice has led to the emergence of the microbiological industry and to a significant expansion of microbiological research in various branches of industry and agriculture. The use of microorganisms in agriculture has increased dramatically. The production of bacterial fertilizers has increased, in particular nitragin, which is prepared from cultures of nodule bacteria that fix nitrogen under conditions of symbiosis with leguminous plants and is used to infect seeds of leguminous crops. New direction of page - x. microbiology is connected with microbiological methods of struggle against insects and their larvae - wreckers of page - x. plants and forests. Bacteria and fungi that kill these pests with their toxins have been found, and the production of appropriate drugs has been mastered. Dried cells of lactic acid bacteria are used to treat intestinal diseases of humans and page - x. animals.
2. A brief history of the development of microbiology
The emergence and development of microbiology.
Several thousand years before the emergence of microbiology as a science, man, not knowing about the existence of microorganisms, widely used them for the preparation of koumiss and other fermented milk products, for the production of wine, beer, vinegar, for ensiling fodder, and flax lobe. Bacteria and yeast were first seen by A. Leeuwenhoek , who examined dental plaque, herbal infusions, beer, etc. with the help of microscopes he made. The creator of microbiology as a science was L. Pasteur who elucidated the role of microorganisms in fermentations (winemaking, brewing) and in the occurrence of animal and human diseases. Of exceptional importance for the fight against infectious diseases was the method of preventive vaccinations proposed by Pasteur, based on the introduction of weakened cultures of pathogenic microorganisms into the body of an animal or person. Long before the discovery of viruses, Pasteur proposed vaccination against a viral disease - rabies. He also proved that in modern terrestrial conditions spontaneous generation of life is impossible. These works served as a scientific basis for the sterilization of surgical instruments and dressings, the preparation of canned food, the pasteurization of food products, etc. Pasteur's ideas about the role of microorganisms inmatter cyclein nature were developed by the founder of general M. in Russia, S. N. Vinogradsky , who discovered chemoautotrophic microorganisms (assimilate atmospheric carbon dioxide due to the energy of oxidation of inorganic substances; chemosynthesis), nitrogen-fixing microorganismsand bacteria that decompose cellulose under aerobic conditions. His student V.L. Omelyansky discovered anaerobic bacteria that ferment, that is, decompose cellulose under anaerobic conditions, and bacteria that form methane. A significant contribution to the development of microbiology was made by the Dutch school of microbiologists who studied the ecology, physiology, and biochemistry of various groups of microorganisms (M. Beijerinck, A. Kluyver, K. van Niel). An important role in the development of medical microbiology belongs to R. Kohu , who proposed dense nutrient media for growing microorganisms and discovered the pathogens of tuberculosis and cholera. Development of medical microbiology and immunology E. Behring (Germany), E. Roux (France), S. Kitazato (Japan), and in Russia - I.I. Mechnikov , L. A. Tarasevich , D. K. Zabolotny , N. F. Gamaleya .
3. Significance of Pasteur's work in the development of microbiology
For the first time, bacteria and yeast were seen by A. Leeuwenhoek, who examined dental plaque, herbal infusions, beer, etc. with the help of microscopes he made. The creator of microbiology as a science was L. Pasteur, who elucidated the role of microorganisms in fermentations (winemaking, brewing) and in the occurrence of animal and human diseases. Of exceptional importance for the fight against infectious diseases was the method of preventive vaccinations proposed by Pasteur, based on the introduction of weakened cultures of pathogenic microorganisms into the body of an animal or person. Long before the discovery of viruses, Pasteur proposed vaccination against a viral disease - rabies. He also proved that in modern terrestrial conditions spontaneous generation of life is impossible. These works served as a scientific basis for the sterilization of surgical instruments and dressings, the preparation of canned food, the pasteurization of food products, etc. Pasteur's ideas on the role of microorganisms in the circulation of substances in nature were developed by S. N. Vinogradsky, the founder of general meteorology in Russia.
Pasteur Louis (1822-1895), French microbiologist and chemist, founder of modern microbiology and immunology. The first director of the research microbiological institute (Pasteur Institute), established in 1888 with funds raised by international subscription. At this institute, along with other foreign scientists, Russians also worked fruitfully - I. I. Mechnikov, S. N. Vinogradsky, N. F. Gamaleya, V. M. Khavkin, A. M. Bezredka and others. connection between theory and practice. From 1857 he studied the processes of fermentation (lactic acid, alcohol, acetic, butyric, discovered by him). Contrary to the prevailing "chemical" theory of the German chemist J. Liebig, he proved that fermentation is caused by the activity of various types of microorganisms. At the same time, he discovered the phenomenon of anaerobiosis (the ability to live in the absence of free O 2) and the existence of obligate (strictly) anaerobic bacteria. He showed that fermentation serves as a source of energy for the microorganisms that cause it. He laid the scientific foundations for winemaking, brewing and other branches of the food industry. He proposed a method for protecting wine from spoilage (pasteurization), which was then used in the production of other food products (beer, milk, fruit and berry juices). He finally refuted (by experiment) the idea of the possibility of spontaneous generation of living beings in modern conditions.
Having studied the nature of the silkworm disease (1870), Pasteur established the contagiousness of the disease, the time of its maximum manifestation, and recommended measures to combat it. He studied a number of other contagious diseases of animals and humans (anthrax, puerperal fever, rabies, chicken cholera, rubella of pigs, etc.), finally establishing that they are caused by specific pathogens. Based on the idea he developed about artificial immunity, he proposed a method of protective vaccinations, in particular, vaccination against anthrax (1881). In 1880, together with E. Roux, Pasteur began research on rabies. The first protective vaccination against this disease was given to him in 1885.
4. The creative contribution of Russian scientists to the development of microbiology (Vinogradsky, Ivanovsky, Omelyansky, Voronin, Khudyakov, Kononov, Mishustin, etc.)
Pasteur's ideas about the role of microorganisms in the circulation of substances in nature were developed by the founder of general microbiology in Russia S. N. Vinogradsky, discoverer of chemoautotrophic microorganisms(assimilate atmospheric carbon dioxide due to the energy of oxidation of inorganic substances; Chemosynthesis), nitrogen-fixing microorganisms and bacteria that decompose cellulose under aerobic conditions. Vinogradsky Sergey Nikolaevich [.1856 -1953], Russian microbiologist, corresponding member of the St. Petersburg Academy of Sciences. In 1891-1912 he was the head of the department of general microbiology at the Institute of Experimental Medicine in St. Petersburg. Actively participated in the organization of the Russian Microbiological Society (1903) and for the first 2 years was its chairman. In 1922 he left for France and until the end of his life he headed the Agrobacteriological Department of the Pasteur Institute near Paris.Vinogradsky was the first to prove that there are special microorganisms (anorgooxidants) that obtain energy as a result of the oxidation of inorganic substances. The resulting energy is used to assimilate carbon dioxide or carbonates; the process of assimilation of carbon dioxide based on this is called chemosynthesis. The discovery of chemosynthesis by Vinogradsky made it possible for Russian microbiology to occupy a leading position and had a great influence on its development in other countries. In 1893, Vinogradsky was the first to isolate the anaerobic spore-bearing bacterium Clostridium Pasteurianum, which assimilates molecular nitrogen, from the soil. His student V. L. Omelyansky discovered anaerobic bacteria that ferment, that is, decompose cellulose under anaerobic conditions, and bacteria that form methane.Omelyansky Vasily Leonidovich, Russian microbiologist, academician of the Academy of Sciences of the USSR (1923; corresponding member 1916). A student of S. N. Vinogradsky. Graduated from St. Petersburg University (1890). In 1893-1928 he worked in the Department of General Microbiology of the Institute of Experimental Medicine, from 1912 the head of the department. The main work on elucidating the role of microorganisms in the cycle of nitrogen and carbon in nature. He proposed methods for the isolation and cultivation of nitrifying bacteria, studied their morphology and physiology. For the first time, he isolated cultures of anaerobic and spore-bearing bacteria that ferment fiber with the formation of organic acids and hydrogen. He studied an aerobic nitrogen-fixing bacterium (of the genus Azotobacter) and proved the existence of bacteria that form methane from ethyl alcohol. He established that the amount of nitrogen assimilated by nitrogen-fixing microorganisms is proportional to the assimilation of organic matter. The first pointed to the possibility of using microorganisms as chemical indicators. Editor of the journal "Archive of Biological Sciences" (1906-28). His books Fundamentals of Microbiology (1909) and Practical Guide to Microbiology (1922) contributed to the formation of several generations of Soviet microbiologists. . Dmitry Iosifovich Ivanovsky(1864 - 1920) - Russian plant physiologist and microbiologist, founder of virology. He graduated from St. Petersburg University in 1888 and was left at the Department of Botany. Under the guidance of A. N. Beketov, A. S. Famintsyn and X. Ya. Gobi studied plant physiology and microbiology.
He discovered crystalline inclusions (“Ivanovsky crystals”) in the cells of diseased plants, thus opening a special world of pathogens of non-bacterial and non-protozoal nature, later called viruses. Ivanovsky considered them as the smallest living organisms. In addition, Ivanovsky published works on the features of physiological processes in diseased plants, the effect of oxygen on alcoholic fermentation in yeast, the state of chlorophyll in plants, its resistance to light, the importance of carotene and xanthophyll, and on soil microbiology.
Voronin Mikhail Stepanovich- botanist (1838 - 1903). Numerous scientific works of Voronin concern mainly the class of fungi (mycology) and those lower organisms that stand on the verge between animals and plants. He discovered, studied in detail and described many lower organisms that are highly important not only in the botanical but also in the general biological sense. The fungal disease of sunflower was discovered and studied by him; the same must be said about the disease of cabbage plants, etc. All of Voronin's works are distinguished by great accuracy. His drawings, without which the latest morphology cannot do, are exemplary.
Khudyakov Nikolai Nikolaevich(1866-1927) - Russian microbiologist. The works are devoted to issues anaerobiosis and soil microbiology. In the work "On the study of anaerobiosis" (1896) he established the possibility of cultivating anaerobes in the presence of oxygen and stated that anaerobiosis in bacteria is an adaptation to the conditions of existence. In the field of soil microbiology discovered the adsorption of bacteria by soil particles, which is of great importance for their activity in soil processes. The author of the first in Russian. the language of the course "Agricultural Microbiology" (1926), which was of great importance for the development of microbiology in the USSR.
- Morphology and taxonomy of bacteria
There are three main forms of bacteria - spherical, rod-shaped and tortuous.
spherical bacteria, or cocci
Form spherical or oval.
micrococci- isolated cells.
diplococci- arranged in pairs.
streptococci- cells of a rounded or elongated shape that make up a chain.
Sarcins - arranged in the form of "packages" of 8 or more cocci.
Staphylococci- cocci arranged in the form of a bunch of grapes as a result of division in different planes.
rod-shaped bacteria
Form rod-shaped, the ends of the cell can be pointed, rounded, chopped off, split, expanded. Sticks can be regular and irregular in shape, including branching, for example, in actinomycetes.
By the nature of the arrangement of cells in smears, they distinguish:
Monobacteria- located in separate cells.
Diplobacteria - arranged in two cells.
streptobacteria- after division, they form chains of cells.
Rod-shaped bacteria can form spores: bacilli and clostridia.
Convoluted bacteria
Form- a curved body in one or more turns.
vibrios- the curvature of the body does not exceed one turn.
Spirochetes- bends of the body in one or more turns.
Bacteria size
Microorganisms are measured in micrometers and nanometers.
The average size of bacteria is 2 - 3 x 0.3 - 0.8 microns.
Shape and size are important diagnostic features.
The ability of bacteria to change their shape and size is called polymorphism.
Questions for the exam
by discipline "Agricultural microbiology"
for engineering students
specialties 1-74 02 01 Agronomy
1. Microbiology as a biological science. Subject and methods of research.
2. History of the development of microbiology. Morphological, physiological, biochemical, ecological and genetic period of development.
3. The main tasks and directions of development of microbiology at the present stage.
4. Distribution and role of microorganisms in nature.
5. Prokaryotic and eukaryotic microorganisms, their cellular organization and main differences.
6. The main forms of bacteria and their sizes.
7. General scheme of the structure of a bacterial cell.
8. External structures of a bacterial cell (capsule, outgrowths). movement of bacteria.
9. Structure, chemical composition and functions of the bacterial shell. Gram-positive and gram-negative bacteria, L-forms.
10. Structure and functions of the cytoplasmic membrane. Mesosomes.
11. Cytoplasm and its structures (nucleoid, ribosomes, inclusions).
12. Endospores: formation, structure and properties. Other resting forms.
13. Location of spores in the cell. Germination of spores.
14. Methods of reproduction of prokaryotes. Growth of cell mass of microorganisms on nutrient media.
15. Principles of taxonomy and nomenclature of microorganisms, taxonomic categories. The concept of strain and clone.
16. Systematics according to D. Bergi. Classification criteria.
17. General characteristics of department 1 - Gracilicutes. Bacteria, bacteria with anoxic and oxygen type of photosynthesis.
18. General characteristics of department 2 - Firmicutes. Firmibacteria and tallobacteria.
19. General characteristics of department 3 - Tenericutes. Mycoplasmas.
20. General characteristics of department 4 - Mendosicutes. Archaebacteria.
21. Actinomycetes, their systematic position, structure and reproduction. The value of actinomycetes in the soil-forming process.
22. Microscopic fungi: mucor, penicillium, aspergillus. Yeast.
23. Practical use of molds and yeasts.
24. Viruses: structure, properties, classification. Viroids and prions.
25. Structure and reproduction of bacteriophages. Virulent and temperate phages.
26. Hereditary factors of bacteria. Nucleoid and plasmids.
27. Mutational and recombinative variability in prokaryotes.
28. Transformation, conjugation and transduction as sources of hereditary variability.
29. Practical use of genetic engineering in microbiology.
30. Methods of nutrition and intake of nutrients into the cell.
31. Chemical composition and nutritional needs of microorganisms.
32. The main types of nutrition of microorganisms in relation to energy sources, hydrogen donor, carbon source.
33. Sources of nitrogen and vitamins in microorganisms. Assimilation of ash elements.
34. Nutrient media for growing microorganisms. Classification by consistency, by purpose, by origin.
35. The concept of metabolism: anabolism and catabolism.
36. The main ways of obtaining energy by microorganisms: aerobic respiration, incomplete oxidation, anaerobic respiration, fermentation.
37. Influence on microorganisms of humidity and concentration of solutions. Osmophilic and halophilic organisms.
38. The ratio of microorganisms to temperature. Thermal sterilization methods.
39. Impact on organisms of light, radiation, pressure, ultrasound, electricity, mechanical shocks.
40. The ratio of microorganisms to oxygen.
41. The influence of the acidity of the environment on the development of microbes.
42. The action of chemically toxic substances on microorganisms. Disinfection and antiseptics.
44. Antibiotics of microbial and animal origin, phytoncides.
45. Theoretical foundations of methods of storage, processing and conservation of food products.
46. Carbon cycle in nature and the role of microorganisms.
47. Alcoholic and glycerin fermentation. Pathogens, conditions, chemistry and meaning.
48. Lactic acid fermentation: homofermentative and heterofermentative.
49. Pathogens, conditions, chemistry and significance.
50. Propionic acid fermentation. Pathogens, conditions, chemistry and meaning.
51. Butyric and acetone-butyl fermentation. Pathogens, conditions, chemistry and meaning.
52. Decomposition of pectin substances. Pathogens, conditions, chemistry and meaning. Rosy lobe of flax.
53. Decomposition of starch. Pathogens, conditions, chemistry and meaning.
54. Obtaining acetic and citric acids. Pathogens, conditions, chemistry and meaning.
55. Oxidation of fats by microorganisms. Pathogens, conditions, chemistry and meaning.
56. General scheme of the nitrogen cycle in nature.
57. Ammonification of proteins. Pathogens, conditions, chemistry and meaning.
58. Immobilization of nitrogen in the soil. The influence of this process on the nitrogen nutrition of plants.
59. Nitrification. Pathogens, conditions, chemistry and meaning.
60. Denitrification: direct and indirect. Pathogens, conditions, chemistry and meaning.
61. Biological fixation of molecular nitrogen. Its essence and chemistry.
62. Free-living nitrogen-fixing microorganisms: Clostridiumpasteurianum,Azotobacter,Beijerinskia ,Derxia,Azomonas, cyanobacteria.
63. Symbiotic nitrogen fixation in legumes and non-legumes. Characteristics of the genus Rhizobium and Frankia. Optimal conditions for nitrogen fixation. bacterial preparations.
64. Associative nitrogen fixation in the rhizosphere and phyllosphere. Characteristic azospirillum,pseudomonas,Klebsiella,Flavobacterium and their use.
65. Cycle of sulfur in nature: mineralization, sulfification and desulfurization. Pathogens, conditions, chemistry and meaning.
66. Cycle of phosphorus in nature. Mineralization of organic phosphorus and mobilization of phosphates.
67. The cycle of iron in nature. Pathogens, conditions, chemistry and meaning.
68. Soil as a habitat for microorganisms.
69. Participation of microorganisms in the soil-forming process.
70. Methods for determining the composition and activity of soil microorganisms. The method of breeding and sowing on dense nutrient media, the method of direct counting.
71. Microflora of various types of soils. Microorganisms-indicators.
72. Influence of tillage, fertilizers and pesticides on the activity and species composition of soil microflora.
73. The use of microbial preparations in the control of pests and diseases of agricultural crops.
74. Microflora of rhizoplane and rhizosphere. Mycorrhiza. role in plant life.
75. Microflora of the phyllosphere, its composition and role in plant life. Grain microflora and its changes under different storage conditions.
76. Microbiological processes during hay drying and silage.
77. Feed ensiling. Vigorous plants. Silo quality indicators.
78. Spread of microorganisms in water. Water treatment methods and the use of microorganisms.
79. Quantitative and qualitative composition of air microflora.
80. Spread of infectious diseases through water and air.
81. Application of bioconversion methods in agriculture.
Compiled by:
Associate Professor of the Department, Ph.D.S. Freezing
Agricultural biology, 2011, no. 3, p. 3-9.
UDC 631.46:579.64 :)
